My girlfriend and I made the dubious choice of buying several hundred dollars worth of clothing from sammydress. If you can ignore sammydress not having our sizes, and not having the stock (so we needed to wait), you can't ignore their website losing our order, and their staff hardly speaking any English. They hardly ever answer their phones, and the responses you get back from both their online customer disservice and their phone staff are barely intelligible, and almost completely ignore your questions and requests. This business is not setup to offer support. If you manage to get an item that fits you (very few of their sizes are as per their site's measurements), then you're lucky. They only feature reviews of happy clients on their site - I doubt any of these reviews are legit. You have to come to sites such as this one to get real feedback from real ex-customers.
On a positive note: the quality of the garments is decent, and my girlfriend likes many of the dresses she received from them. If you're willing to wait many many weeks and not get any sensible or helpful responses, then you can roll the dice and take your chances. Sammydress delete ALL your prior correspondence from their site's support tickets regularly and at their whim - so you'll need to keep a local record of all correspondence. I suspect that they're covering their rear ends to make it more difficult for you to get a refund.
Update (24 Mar 2016): After several mostly time wasting emails with sammydress, they refunded US$100 towards my order. This is a fraction of the total order value. Their inflated exorbitant postage charges boost their profit margins, while your return postage costs ensure that you'll never send anything back to them. They know this, and confirm this in conversations. So they're counting on you not returning anything. The only way in which to get a refund, even if partial like mine, is by posting a review as I have done on this site, or by paying via paypal and asking for a refund via paypal.